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We would love to provide everyone an ad-free experience, but we do need to generate revenue to cover at least some
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In addition, we continue to offer -- pro bono -- our KenKen Classroom
Program which provides free KenKen puzzles
and lessons to over 1 million students weekly. Revenue we raise from advertisements and subscription sales allow us
to keep the program going, plain and simple. So thank you for supporting these teachers and students by supporting
us. We all appreciate it.

ALL-NEW TECHNOLOGY

The KenKen player you are now using has been recoded into state-of-the-art
HTML5 language instead of Adobe Flash. Enjoy!

FASTER, SMOOTHER PERFORMANCE!

Your new experience should be faster, smoother, and more enjoyable
than ever before.
While you may notice some subtle differences, puzzle play should be
exactly the same as always...just better! If you have questions or comments,
please email us at info@kenken.com.

Solving Tips

Solving Tips

Now matter what your KENKEN skill level is, it never hurts to have a few extra strategies and shortcuts in your back pocket. (OK, you don’t have to actually keep them in your pocket.) Here are “rules of thumb” for different scenarios you’ll encounter in the puzzles.
This tutorial, by David Levy, KENKEN’s technology expert, appears in KENKEN: Books 1 - 4: The New Brain-Training Puzzle Phenomenon, which HarperCollins in Britain published.

Overall Strategies

• Write each candidate in every unsolved square. Then look at the unsolved squares one by one, and see if you can eliminate any of the candidates by using the rule that no digit may appear more than once in any row or column, and every digit must appear exactly once in every row and column. When you have done this for every unsolved square on the grid, you may to be able to fill in at least one of them. If so, repeat the process, as your newly filled-ins square(s) should lead to even more.

• If any two squares in the same row or column have the same two candidates, then neither of those candidates can be in any other square in the same row or column. The same rule applies to three squares with exactly three shared candidates, four squares with four shared candidates, and so on.
*Note: This rule applies for any number of squares.

Example: You’ve determined that the only candidates for the middle two boxes are 2 and 4. Therefore, the far-left box cannot be 2 or 4, as those numbers must be shared between the middle two boxes. Since 3 is already used, the far-left box must be 1.

Unique Situations

Any Grid Size
In a 2x cage with two squares, the candidates must be 1, 2.

In a 3+ cage with two squares, the candidates must be 1, 2.

In a 3x cage with two squares, the candidates must be 1, 3.

An L-shaped 3x cage with three squares must have the numbers arranged like this:
In a 4+ cage with two squares, the candidates must be 1, 3.

An L-shaped 4+ or 2x cage with three squares must have the numbers arranged like this:
In a 5x or 5÷ cage with two squares, the candidates must be 1, 5.

An L-shaped 5x cage with three squares must have the numbers arranged like this:

In a 6+ cage with 3 squares in a line the candidates must be 1,2,3
In a 6+ cage with three squares in the same row or column, the candidates must be 1, 2, 3.
In a 6x cage with three squares in the same row or column, the candidates must be 1, 2, 3.
In a 7+ cage with three squares in the same row or column, the candidates must be 1, 2, 4.
In a 10x cage with three squares in the same row or column, the candidates must be 1, 2, 5.
In a 15x cage with two squares, the candidates must be 3, 5 .
In a 15x cage with three squares in the same row or column, the candidates must be 1, 3, 5.
In a 20x cage with two squares, the candidates must be 4, 5.
In a 20x cage with three squares in the same row or column, the candidates must be 1, 4, 5.

4x4 or Larger
In a 6+ cage with three squares in the same row or column, the candidates must be 1, 2, 3.
In a 6x cage with three squares in the same row or column, the candidates must be 1, 2, 3.
In an 8x cage with three squares in the same row or column, the candidates must be 1, 2, 4.

3x3
An L-shaped 4x cage with three squares must have the numbers arranged like this:

4x4
In a 3– cage with two squares, the candidates must be 1, 4.
In a 6+ cage with two squares, the candidates must be 2, 4.
In a 7+ cage with two squares, the candidates must be 3, 4.
In a 4x or 4÷ cage with two squares, the candidates must be 1, 4.
In a 6x cage with two squares, the candidates must be 2, 3.
In an 8x cage with two squares, the candidates must be 2, 4.

5x5
In a 4– cage with two squares, the candidates must be 1, 5.
In a 6x cage with two squares, the candidates must be 2, 3.
In a 9+ cage with two squares, the candidates must be 4, 5.
In an 8+ cage with two squares, the candidates must be 3, 5.
In an 8x cage with two squares, the candidates must be 2, 4.
In a 12x cage with two squares, the candidates must be 3, 4.
In a 12x cage with three squares in the same row or column, the candidates must be 1, 3, 4.
In a 60x cage with three squares in the same row or column, the candidates must be 3, 4, 5.

6x6
In a 5– cage with two squares, the candidates must be 1, 6.
In an 11+ cage with two squares, the candidates must be 5, 6.
In a 10+ cage with two squares, the candidates must be 4, 6.
In a 15+ cage with three squares in the same row or column, the candidates must be 4, 5, 6.
In an 18x cage with two squares, the candidates must be 3, 6.
In an 18x cage with three squares in the same row or column, the candidates must be 1, 3, 6.
In a 14+ cage with three squares in the same row or column, the candidates must be 3, 5, 6.
In a 120x cage with three squares in the same row or column, the candidates must be 4, 5, 6.

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No matter what you're looking for — learning or fun — KenKen.com has it! Free online puzzles.
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Visit our For Teachers section for math teacher resources, our free KenKen Classroom program, and a message
from Tetsuya Miyamoto, the Japanese educator behind KenKen. Miyamoto, chess master David Levy, and the rest of
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KenKen? Check out our Will Shortz Presents books. Try our mobile app on iPhone and iPad or our Kindle version.
Play on the New York Times puzzle page and NCTM website. Regardless of why, how, or where you play, KenKen are
the math puzzles that make you smarter!